refactor(benchmark): remove unused markers and update docstring for clarity

Author: LouisTsai-Csie

src/ethereum_test_specs/benchmark.py

@@ -1,7 +1,7 @@
 """Ethereum benchmark test spec definition and filler."""
 
 import math
-from typing import Callable, ClassVar, Dict, Generator, List, Optional, Sequence, Type
+from typing import Callable, ClassVar, Generator, List, Optional, Sequence, Type
 
 from pydantic import Field
 
@@ -28,12 +28,11 @@
 
 class BenchmarkTest(BaseTest):
     """
-    Filler type designed specifically for benchmark test cases.
+    Test type designed specifically for benchmark test cases.
 
     This test type is designed specifically for benchmark test cases and supports:
-    - High compatibility with both blockchain_test and state_test formats
+    - High compatibility with blockchain_test format
     - Support for EIP-7825 transaction gas limit cap (2^24)
-    - Only generates blockchain_test format as output
     - Automatic splitting of tests when gas limit exceeds the cap
     """
 
@@ -56,10 +55,6 @@ class BenchmarkTest(BaseTest):
         ),
     ]
 
-    supported_markers: ClassVar[Dict[str, str]] = {
-        "benchmark_test_only": "Only generate a benchmark test fixture",
-    }
-
     def split_transaction(self, tx: Transaction, gas_limit_cap: int | None) -> List[Transaction]:
         """Split a transaction that exceeds the gas limit cap into multiple transactions."""
         if (gas_limit_cap is None) or (tx.gas_limit <= gas_limit_cap):